At least 30 percent of malware today is new, zero-day malware that is missed by traditional antivirus defenses, according to a new report.

"We're gathering threat data from hundreds of thousands of customers and network security appliances," said Corey Nachreiner, CTO at WatchGuard Technologies. "We have different types of malware detection services, including a signature and heuristic-based gateway antivirus. What we found was that 30 percent of the malware would have been missed by the signature-based antiviruses."